Comparative Evaluation of Osteonecrosis of the Femoral Head Classification: CJFH Classification versus JIC Classification

Abstract

To compare China-Japan Friendship Hospital (CJFH) classification with Japanese Investigation Committee (JIC) classification by observing the regular progressive pattern of nontraumatic osteonecrosis of femoral head (ONFH) to establish the reliable and convenient new classification of ONFH. The coronal section of the femoral head was divided into three pillars (medial, central, and lateral). The midcoronal section of the femoral head on MRI was selected. The CJFH classification of ONFH was established according to the site of necrotic focus in three pillars. Total 153 hips with ONFH were classified according to CJFH and JIC classifications, respectively. The collapse rate was observed and compared between both classifications of ONFH. The CJFH classification for ONFH consists of three types: type M, the medial pillar was involved; type C, the medial and central pillars were involved; and type L, the lateral pillar was involved. According to site of necrosis focus in the lateral pillar, the type L was divided into three types: L1, there pillars were involved, but there still was some normal tissue in lateral pillar; L2, partial central pillar and all lateral pillar were involved; L3, the whole femoral head was involved. The natural history of the ONFH showed the collapse rate of types L2 and L3 in CJFH classification (95.3%) was higher than that (72.3%) of type C2 in JIC classification. The CJFH classification of ONFH based on three pillars is more applicable than JIC classification in predicting collapse of the femoral head.